Ultra-efficient photocatalysts for photoelectrochemical water splitting

ABSTRACT:

An efficient way to combat the energy crisis and the greenhouse gas effect of fossil fuels is the production of hydrogen fuel from solar-driven water splitting reaction. This talk will show that nanostructured materials of transparent conducive oxides (such as titania or zirconia) can be used as high-performance catalysts with a high photoconversion efficiency that makes it potentially viable for commercial solar hydrogen production. The trick here is to introduce both chemical defects (oxygen vacancies) and physical defects (partial delamination) as the means to enhance the efficiency. For zirconia nanowire film, the resulting photocathode provides the highest overall photocurrent (−42.3 mA per sq cm at 0 V vs RHE) among all the photocathodes reported to date, and an outstanding 3.1% half-cell solar-to-hydrogen conversion efficiency with a Faradaic efficiency of 97.8%. Even more remarkable is that the majority of the photocurrent (69%) is produced in the visible light region. Other solar-related work on-going at WATLab will also be discussed.